Throttle control for aircraft engines



1948" H. A. ALEXANDERSON 2,453,652

THROTTLE CONTRO L FOR AIRCRAFT ENGINES Original Filed Nov. 2, 194a 7 sheets-sheen INVENTOR' Howe/J24 AIQa-ana EJ BY Jamaa ATTORNEY N 1943- H. A. ALEXANDERSON 2,453,652

THROTTLE CONTROL FOR AIRCRAFT ENGINES Original Filed Nov. 2, 4 v 7 Sheets-Sheet 2 INVENTOR I flowardA. Alex azzale'raolz ATTORNEY Nov. 9, 1948. H. A. ALEXANDERSON THROTTLE CONTROL FOR AIRCRAFT ENGINES" I 7 Sheets-Sheet 3 Original Filed Nov. 2, 19%

5132 NEE OJOLZ2 E H. A. ALEXANDERSON THROTTLE CONTROL FOR AIRCRAFT ENGINES Original Filed Nov. 2. 1943 Nov. 9, 1948.

'7 Sheefs-Sheet 4 Nov. 9, 1948. v H. A. ALEXANDERSON 2,453,652

THROTTLE CONTROL FOR AIRCRAFT ENGINES Original Filed Nov. 2. 94 7 Sheets-Sheet 5 I N V EN TOR. Howard A .A [exclude-Sal.

THROTTLE CONTROL FOR AIRCRAFT ENGINES Original Filed Nov. 2. 1943 Sheets-Sheet 6 a d, ATTORNEY H. A. ALEXANDERSON THROTTLE CONTROL FOR AIRC-RAFT ENGINES Original Filed Nov. 2. 1943 Nov. 9, 1948.

7 Sheets-Sheet 7 8\ %Q\ m I m Y 3 .v V mw Q Q N m N9 QNQQW A h ..wwu 5 N i i w T vw N Patented Nov. 9, 1948 THROTTLE CONTROL FOR AIRCRAF ENGINES Howard A. Alexanderson, Wood-Ridge, 1., as-

signor to Bendix Aviation Corporation, Teterboro, N. J., a corporation of Delaware "Continuation of application Serial No. 508,724,

This application October 31, 1947, Serial No. 783,237

November 2, 1943.

The present application is a continuation of my application Serial No. 508,724, filed November 2, 1943, and now abandoned. I

My present invention relates to improved control devices and systems of the class disclosed by Patent No. 2,088,954, granted to David Gregg under date of August 3, 1937, and Patent No. 1,978,- 863, granted to David Gregg and Wesley L. Smith under date of October 30, 1934, both of which patents are owned by the assignee of the present invention.

More specifically, the present invention relates to a novel and improved control mechanism for regulating automatically the intake manifold pressure of an internal combustion aircraft engine in accordance with predetermined intake manifold pressure values determined by an adjustable control member.

An object of my invention is to provide novel means responsive to the intake manifold pressure for adjusting a carburetor throttle so as to approximate predetermined pressure values and novel manually adjustable means for selecting such pressure values.

Another object of my invention is to provide a novel adjustment means for directly actuating an automatic carburetor throttle-control in a first sense, and a second novel intake manifold pressure responsive means for directly actuating the throttle control in an opposite sense, and the first and second means acting upon the throttle control through a novel floating lever arrangement.

Another. object of my invention is to provide novel safety means for preventing the automatic carburetor throttle control from opening the throttle past a predetermined maximum open throttle position so that further opening of the throttle past such position may be affected only through adjustment of the manual control. Thus there may be avoided possible damage to the control mechanism and confusion to the pilot through the operation of the automatic throttle control under conditions which would otherwise cause the automatic control to call for further opening of the throttle past its maximum open position. Iiurther, such safety feature provides means whereby the opening of the throttle past the predetermined open position may be placed directly under the control of the pilot and thus provide for more positive control of the engine at such extreme position of the throttle.

Another object of my invention is to provide a further novel safety means for efiecting a lock out of the automatic control means so as to pres vent the automatic opening of the throttle upon 38 Claims. (Cl. 123-103) the manual control being adjusted to a predetermined minimum pressure selecting position so that further closing of the throttle may be aflected through adjustment of the manual control. Thus I have provided safety means for affecting a positive manual control for closing the throttle to the extreme or fully closed position, and means for fully closing the throttle regardless of the pressure within the intake manifold or the condition of the pressure responsive control mechanism which might otherwise cause the automatic control means throttle.

A further object of my invention is to provide novel means for regulating the intake manifold pressure so as to compensate for changes therein due to variations in atmospheric pressure or other conditions afiecting such pressure.

Another object of my invention is to provide in combination with a first control lever for an automatic throttle control, a second lever for directly controlling the throttle so that any adjustment made by such automatic throttle control in response to th first control lever will be subject at all times to the adjustment of said second lever.-

Another object of my invention is to provide novel means whereby the throttle may at all times be subject to manual control while retaining the automatic features noted.

' A further object of 'my invention is to provide to prevent the full closure of the novel manually adjustable means for varying the limits of the automatic control of the throttle.

It is also an object .of my invention to provide novel control means whereby the throttle may be conveniently adjusted from the cabin of a p1ane for conditions affecting the engine due to variables not reflected merely in the intake manifold pressure so that the aforenoted automatic adjustment of the throttle may be subject at all times to the discretion of the pilot.

Other objects and advantages of this invention are set forth in the following description, taken with the accompanying drawings; andthe novel features thereof are pointed out in the appended claims. The disclosure, however, is illustrative only and changes may be made in detail, especially in matters of shape, size and arrangement of parts within the principle-of the invention, to the full extent indicated by the meanings of the terms in which the appended claims are exand with certain parts broken away for clarity and illustrating in full lines the operation of my novel safety means upon the throttle being adjusted to a full open position and showing, in dotted lines the relative position of the parts upon the main pressure control being adjusted so as to decrease the relative pressure at the intake manifold.

Figure 2 is a sectional view of Figure 1 taken along the lines 2--2 with the parts in the dotted line position and with certain of the parts broken away so as to better. illustrate the structure of the valve stop actuating arm.

Figure 3 is a sectional view of Figure 1 taken along the lines 3--3 and looking in the direction of the arrows.

Figure 4 is a diagrammatic view of my control device illustrating the mode of operation.

Figure 5 is an enlarged end view of my control device.

Figure 6 is a side view of Figure 5 looking in the direction of the arrows 6-6.

Figure 7 isa view illustrating graphically the operative characteristics of my automatic throttle control as compared to the operative characteristics of a manual throttle control applied to a given internal combustion engine at assumed sea level atmospheric pressure conditions.

Figure 8 is a diagrammatic sketch of a modified form of my invention.

The form of my invention illustrated diagrammatically in Figure 4 is preferably operated by a main control lever I which may be conveniently mounted within the cabin of a plane for operation by the pilot. As shown by full lines in Figure 4, the main control lever I has been adjusted to a relative pressure increase position, while the same is shown in dotted lines in a relative pressure decrease position. At one end of the main control lever I is provided an operative knob 2. At the opposite end of the main control lever I there is pivotally connected a main control rod 3. The main control lever I may be pivotally mounted within the cockpit of the plane at a point 4 positioned intermediate the opposite ends of the control lever I.

As shown in Figures 4 and 5, there is pivotally connected at the opposite end of the main control rod 3, an arm 5 mounted on a main control shaft 6 and positioned exteriorly of a casing I. The casing I houses my novel control mechanism and may be conveniently mounted on a bracket IA as shown in Figure 5.

As shown in Figures 2 and 5, there is formed integral with the arm 5, a second arm 8 likewise mounted on the main control shaft 6 and positioned exteriorly of the casing I. Movement of the arm 8 may be limited as indicated in Figure 4 by a stop 9, which is arranged for engagement by the arm 8 and a second engaging arm III formed integral with the arm 8.

The main control shaft 8 extends into the catsing I and is rotatabiy mounted on anti-frictional roller-bearings, as shown in Figure 2.

Positioned within the casing I and fixedly mounted at the inner end of the main control shaft 6 is a crank pin II. The crank pin II has pivotally mounted at the free end thereof a walking beam I2. The walking beam I2 is pivotally connected at one end to a link I3 which is in turn pivotally connected at the other end to an arm I 4 of a bell crank lever I5, as shown in Figure 1.

The bell crank lever I5 is mounted on a shaft I6.

shown in Figure 5. Mounted at the outer end of the shaft I6 is an arm II having pivotally connected at the free end a-throttle control rod I8 for adjustably positioning a throttle valve I9 positioned within the intake manifold of the carburetor on a conventional aircraft internal combustion engine, as indicated diagrammatically in Figure '4. The throttle valve I9 is located at the inlet of the engine's intake manifold for the control of the intake manifold pressure.

Pivotally connected to the arm 8 previousy described, is one end of a linkage rod 20. The opposite end of the rod 28 is pivotally connected to oneend of a screw threaded bolt 2i which is fastened by adjustment nuts 22 and 23 to one end of a lever arm 24 mounted on a pressure selector cam shaft '25, as shown in Figures 3, 4 and 5. It will be readily seen that by adjusting the nuts 22 and23, the effective length of the bolt 2i may be varied and accordingly the effective length of the lever arm 24 so as to provide a convenient means for adjusting the operative range of the pressure selector cam shaft 25. The cam shaft 25 projects into the casing I and is preferably mounted in an anti-frictional Ibearing, as shown in Figure 3.

The cam shaft 25 has fixedly mounted at the inner end thereof, a cam 26 which may be adjustably positioned by the adjustment of the shaft 25. The cam 26 has provided a variable cam surface 2! which is arranged to bear upon an antifrictional single ball bearing 28 carried within a socket 29 formed Within one end of a lever 36. As shownin Figure 3, the lever 30 is pivotally mounted withinthe casing I at a point intermediate the opposite ends thereof on an eccentric pin 3| which may be adjust'albly positioned for calibration purposes by an adjustment screw 3 IA.

Carried by the lever 30, as shown in Figures 1, 3 and 4, is a torsion spring 32 engaging at one end 33, the lever 30 and at an opposite end 34 a pin 35 mounted within the casing 1 in such a manner that the torsion spring 32 exerts a biasing force upon the lever 30 tending to force the same in a counter-clockwise direction, as viewed in Figures 1 and 4. The effect of the biasing force of the spring 32, therefore, normally causes the anti-frictional ball bearing 28 to ride upon the cam surface 21 of the cam 26.

The lever 38 is pivotally connected at the opposite end from the ball bearings 28 to one end of a floating lever 36. The opposite end of the floating lever 36 is pivotally connected to one end of a linkage arm 31. The linkage arm 31 is operatively connected at the opposite end to a pressure responsive mechanism indicated generally by the numeral 38 and which will be described hereinafter. Y

A third link 39 is pivotally connected at one end to the floating lever 36 at a point intermediate the opposite ends of the lever 36. The opposite end of the link 39 is affixed to a slidably adjustable member 48 for controlling a servovalve of conventional type. The member 45 is slidably mounted within a valve sleeve 4i, positioned within the wall of the casing I. Carried by the servo-valve control 4815 a tension spring 52 which exerts a force biasing the link 39 toward the floating lever 36. The valve sleeve 4| has provided ports 42, 43, 44, 45 and 46, as shown in Figures 1 and 4. The ports 43 and 45 are connected by suitable conduits 41 and 48, respectively, to a servo-motor indicated generally by the numeral 49, while a conduit 56 is connected to the port 44 and serves as an inlet to the servovalve of a suitable fluid medium under pressure servo-motor 45.

of the servo-motor 49. A drain conduit is further connected to the ports 42 and 45 and serves as an outlet for the fluid pressure medium supplied to the servo-valve in the conventional manner.

As shown in Figures 4 and 6 a servo-piston 52 is slidably mounted within a cylinder wall 53 of the The piston 52 is connected to the piston rod 54 in any conventional manner. A tension spring 55 biases the piston 52 in a direction tending toslide the rod 54 outwardly from the cylinder 53 for apurpose which will be explained hereinafter. Movement of the piston- 52 in response to the biasing force of the spring 55 is limited by a collar 55 against which the piston 52 abuts in the extreme biased position.

The conduits 41 and 48, previously described, lead to opposite sides of the piston 62 so that adjustment of the servo-valve control 40 to the left ofthe neutral position shown in Figure 4 will cause the pipe 41 to'serve as an inlet of pressure to the servo-motor 49 and thereby exert a biasing force upon the piston 52 to the right. Likewise, adjustment of the servo-valve control 40 to the right of the neutral position shown in Figure 4, will cause the pipe 48 to serve as an inlet of pressure to the servo motor 49 and exert biasing force upon-thev piston 52 to the left. Thus it will be seen that in the conventional manner v the direction of movement of the piston rod 54 may be controlled by the adjustment of the servovalve control 40.

While I have shown in the present embodiment of my invention a hydraulic control and power means, it will be readily apparent that other forms of controls and power means such as well known mechanical and electronic controls and power means, may be readily substituted therefor.

It will be further noted that the outer end of the piston rod 54 under control of the power means aforesaid, is pivotally connected by a link 63 to the opposite end of the walking beam i2 from that to which the link I3 is connected, as previously described. It will thus be seen that the adjustment of the walking beam l2, and accordingly the throttle control shaft I6 is dependent upon the affect thereon of the adjustment of the main control shaft 6 and the servo-motor 49.

The adjustment of the servo-motor 49 is dependent upon three novel features of my invention, which are, first, the adjustment of the pressure selector cam 26, previously described, secend the position of the pressure responsive mechanism 38, as will be further described, in relation to the adjustment of the pressure selector cam 26, and third, by means to override the pressure responsive mechanism 38 and effective upon the adjustment of the main control shaft 6 irrespective of the position of the pressure selector cam 26 or the pressure responsive mechanism 38. i

The pressure responsive mechanism 38, previously noted, comprises preferably a pair of bellows 5? and 58 mounted within the casing i, as best shown in Figure 1. The bellows 58 is an internal combustion aircraft engine in such a manner that the biasing force of the bellows 51 will vary in response to the intake manifold pressure. A plate BI. is mounted between the bellows 51 in the pressure exerted within the bellows 51, as is well known in the art. The plate 61 has provided a projecting arm 52 to which there is pivotally connected an end of the linkage arm 31 previously described.

From the foregoing it will be seen that the adjustment of the servo-valve control 40 will be dependent upon the intake manifold pressure and thereby increasing the acting upon the pressure responsive mechanism 38 and the corresponding adjustment thereof in relation to the adjustment of the cam 28. It should be pointed out here that the tension exerted by the spring 32 acting upon the arm 3|! has a considerably greater biasing force upon the servo-valve control member 40 than the force exerted. thereon by the relatively light tension exerted by the spring 52 mounted on the member 45, but the biasing forces exerted by the spring elements 32 and 52 have a substantially negligible effect upon the pressure responsive mechanism 38 due to the biasing force exerted by the much stronger spring 59 positioned within the bellows 58 for balancing the biasing force of the pressure within the bellows 5-1.

Thus it will be seen that in normal operation a decrease in the intake manifold pressure due for example to a rise in altitude, decrease in atmospheric pressure or other cause, would affect the bellows 51 and 58 so as to cause the relative contraction of the bellows 51 and the relative expansion of the bellows 58. Such action would cause the movement of the plate 6| and the longitudinal movement of the linkage arm 3i toward the left, as viewed in Figure 1. In normal operation, the spring 32 holds the ball 28 against cam 26 with arm 68 clear of pin 15 as is hereinafter explained.

Since, as previously explained, the spring 32 exerts a greater biasing force than the spring 52, it will be readily seen that such longitudinal movement of the arm 31 would cause the floating lever 35 to pivot in a clockwise direction on .its pivotal connection to the arm 36, resulting in a corresponding longitudinal movement of the link 39 and servo-valve control member til to the left.

Thus with valve control member til first in the neutral position, such adjustment of the servovalue control member 40 would cause the opening of the port 43 to the inlet of the pressure medium provided through the port 44, resulting in the shifting of the piston 52 to the right as viewed in Figure 4 and the mechanical adjustment of the throttle it to a relatively increased open position through the action of the piston rod 5 3 on the link 63, walking beam l 2, link it, bell crank lever I5, throttle control shaft l5, arm ll and rod l8, pressure exerted at the intake manifold.

Conversely, an increase in theintake manifold pressure would causethe relative expansion of the bellows 5i and contraction of the bellows 58, re-

} sulting in the longitudinal movement of the linkpreferably partially evacuated and balanced by the wall it to the intake manifold pressure of age arm 37 to the right.

Obviously, since the counter-clockwise movement of the arm 30 would be prevented by the cam 26, the latter adjustment of the linkage arm 37 would cause the counter-clockwise movement of the floating lever 35 about its pivotal connection to the lever til, causing a corresponding longitudinal movement of the servo-valve control member th to the right. Thus with the valve conand 58 and is movable upon variance trol member first in the neutral position, such adjustment of the servo-valve control member 46 would cause the opening of the port 45 to the inlet 'of the pressure mediu'mprovided through the port 44, causing a shifting of the piston 62 to the left and the mechanical adjustment of the throttle I9 to a relative decreased open position and thereby decreasing the pressure exerted at the intake manifold.

Thus it will be seen that I have provided automatic means for compensating for either an increase or decrease in the pressure at the intake manifold, so that a predetermined standard pressure condition may be approximated. Obviously, upon standard pressure conditions being approximated, the pressure responsive mechanism 38 will cause the adjustment of the servo-valve control member 40 to a neutral position.

It will be further seen that I have provided novel adjustment means whereby the value of the predetermined standard pressure condition may be varied. Thus upon movement of the control lever I, as shown in Figure'4, in a counter-clockwise direction, a clockwise movement of the main control shaft 6. will result, causing a corresponding clockwise movement of the walking beam I2 about its pivotal connection to the link 53 and causing in turn the clockwise movement of the throttle control shaft I6 so as to move te throttle I9 to a relative increased open position.

Furthermore, it will be seen that such adjustment of the control arm I will also cause the clockwise movement of the arm 8 and a corresponding clockwise rotation of the cam 26, as viewed in Figures 1 and 4.

The cam surface 21 is so arranged in relation to the arm 30 that as the cam is rotated in a clockwise direction, the arm 30 following the cam surface 21 under tension of the spring 32 pivots about the pin 3| in a counter-clockwise direction.

Further, with the bellows 51 and 58 in a balanced relation and the servo-valve control mem-' ber in a neutral position, it will be seen that since the spring 32 exerts a greater biasing force than the spring 52 that the latter counter-clockwise movement of the arm 30 will cause the pivoting of the floating lever 36 in a similar counterclockwise direction about its pivotal connection on the arm 31 and cause in turn a longitudinal movement of the link 39 and servo-valve control member 40 to the left as viewed in Figures 1 and 4.

Such movement of the servo valve control member 48, as previously descrlbed,-will then cause an adjustment of the throttle I9 to a'relative increased open position until the increased pressure resulting in the intake manifold causes the bellows 51 to expand effecting a longitudinal movement of the-arm 31 to the right and the readjustment of the servo valve control member 40 to a neutral position. It will be thus seen that such adjustment of the control arm I will cause an increase in the value of the predetermined standard intake manifold pressure.

Conversely an adjustment of the manual control lever I in an opposite or clockwise direction would cause a decrease in the value of the predetermined standard intake manifold pressure.

Thus as the manual control lever I is adjusted in a decrease manifold pressure direction the value of the predetermined standard intake pressure is decreased, while as the control I is adjustcd in the opposite direction this predetermined standard value is increased.

In my present invention I have provided several novel safety features including a novel lock out of the automatic adjustment means whereby upon adjustment of the main control lever I to a" predetermined minimum standard pressure selecting position, the openingof the throttle I9 may be affected only by the manual adjustment of the control lever I without regard to the pressure existing at theintakemanifoldor. the condition of the pressure responsive mechanism. This isspecifically accomplished by provlding an adjustable abutment l and 4. r

The latter feature is claimed generically in my copending application Serial .No. 550,646, filed August 22, 1944, as a division of application Serial No. 417,855, filed November 4, 1941, and now U. S. Patent No. 2,358,845, granted September 26, 1944, and assigned to Bendix Aviation Corporation.

The abutment rod 64 is screw-threaded engaged in the wall I2 and projects through the wall I2 into the bellows 51. A suitable cleft 65 is provided in the abutment rod 64 and is positioned exteriorly of the bellows 51 so that the abutment rod 64 may be conveniently adjusted longitudinally for calibration purposes. The abutment rod 64 is arranged so as to cngage the plate 6| upon the pressure in the intake manifold decreasing to a predetermined low value equal to.

the critical standard value at which the automatic control for opening the throttle is to be discontinued and manual control alone remains.

Thus upon the manual control arm I being adjusted to the critical point for selection of the critical standard pressure value at and below which the automatic control for opening the throttle is to be discontinued. it will be apparent that if the actual pressure in the intake manifold be greater than the predetermined standard, the effect on the bellows 5'! would be to cause the valve control member 40 to be adjusted so as to effect further closing of the throttle I9. However, if the intake manifold pressure be below the critical standard value, the bellows 51 would be prevented by the abutment rod 64 from contracting further so as to otherwise cause a further automatic opening of the throttle I9. Rather under the latter conditions, the opening of the throttle I9 may be accomplished only by positive manual adjustment of the control lever I toward the pressure increase position, while further closing of the throttle I9 may be accomplished by positive manual adjustment of the control lever I toward the pressure decrease position. Thus I have provided a safety means for causing the full closure of the throttle I9 regardless of the conditions acting upon the pressure responsive mechanism 38, which device, however. does not prevent the automatic closing of the throttle in the event of a pressure existing within the intake manifold greater than the value of the adjusted standard pressure value.

A second abutment rod 66 is also mounted within the bellows 58 as shown in Figure 1 for the purpose of limiting the excessive expansion of bellows 51 and contraction of bellows 58 which might otherwise cause mechanical damage thereto.

I have further provided a third safety means for preventing the automatic opening of the throttle I9 past a predetermined maximum critical point, and the said safety means so arranged that such opening of the throttle past such point may only be accomplished under the positive manual control of the lever I.

The latter feature is claimed generically in rod 84 best shown in Figures the copending application Serial No. 440,669, filed April 2, 1942, by Frank C. Mock and assigned to Bendix Aviation Corporation.

In the present invention the foregoing is specifically accomplished by providing the bell crank.

lusted for calibration purposes by means of thescrew 10 which extends through the wall of the casing I to the exterior as shown in Figure 2.

Carried by the arm 68 is a pin 13 on which is mounted a roller the knocker arm 61 as shown in Figure 1. There further projects from the arm 68, a second arm I which is arranged for engagement by a valve actuating stop pin I6 which is slidably mounted within a sleeve member I1 mounted within the wall I2. The pin I6 projects through the sleeve II into the valve sleeve 4| where it is adapted to engage in its inward position, the free end of the servo-valve control rod 40. The pin I6 is normally biased by a spring I8 into a disengaging relation from the rod 00 as shown in Figure 4. In the latter position the pin I8 under the 10 Figure 8 wherein I have provided a throttle control lever I00 whereby the throttle I0 may at all times be kept under manual control, while retaining the automatic features previously noted.

This is specifically accomplished by providing a walking-beam II-which is pivotally connected at a. point I02 intermediate the opposite ends thereof to the free end of described.

An end I03 of the walking-beam IIOI is pivthe arm II previously otally connected to the throttle control rod I8.

' The other end I04 is pivotally connected to one I4 arranged for engagement by biasing force of the spring I8 actuates the arm A 68 in a counter-clockwise direction against a stop pin 79 mounted in the wall I. Upon the throttle It being opened to a predetermined point the bell crank lever I5 will be positioned so as to cause the knocker arm 61 to engage theroller '70 mounted on the arm 00. Continued clockwise adjustment of the bell crank lever I5 will cause arm 68 to actuate the pin I6 inward, as shown in Figure 1, so as to prevent valve control rod 00 from being adjusted through the floating lever 30 to a position to the left of the neutral position. In the latter locked position a decrease in pressure at the intake manifold would cause merely a contraction of the bellows 51 and the actuation of the floating lever 36 so as to cause the clockwise movement of the lever 30 against the biasing force of the spring 32 so as. to disengage the cam 26 as shown in Figure 1.

An increase in pressure above the predetermined standard value set through the adjustment of the cam 25 would of course cause the adjustment of the valve control rod to the right of the neutral position shown in Figure 1 effecting a corresponding decrease in the setting of the throttle I9. From the position shown in Figure 1 an increase in pressure would cause the adjustment first through the floating lever 36 of the arm 30 in a counter-clockwise direction into engagement with the cam 26 and upon continued increase in pressure an adjustment of the valve control rod 90 to the right so as to eilect a decrease in the setting of the throttle I9. A decrease in the intake manifold pressure could not in any event under the setting shown in Figure 1, cause an increase in the setting of the throttle I9.

Thus it will be seen that I have provided means whereby the opening of the throttle I9 past a predetermined critical point can be accomplished only through the adjustment of the manual control I. I

The foregoing features of operation of my invention are illustrated graphically in Figure 7 A modified form of my invention is shown in end of a throttle control rod I05. The opposite end of the throttle control rod I05 is pivotally connected to an end of the throttle control lever which is pivoted at I06 in a throttle control lever quadrant I01, conveniently mounted within the cabin of the plane for operation by the pilot.

The throttle control lever I00 is so arranged that direct control of the throttle l9 may be accomplished irrespective of the automatic control or the pressure standard determined by the lever I. This isspecifically accomplished by providing the quadrant I0I'with sufllcient arcuate range and limiting the range of movement of the servo piston 52 as shown so that any retarding 'efiect which mightotherwise be produced by the manifold pressure setting of the cam 26 through the control lever I as previously explained, may be readily overcome by the adjustment of the lever I00 in an amount in excess of the range of the retarding adjustment of theservo piston 52.

Further, by suitable adjustment of the lever I00 the upper and lower ranges of automatic adjustment of the throttle I9 may be conveniently varied so that automatic operation may be eifected only when the manifold pressure drops below a predetermined minimum value or rises above a predetermined maximum value, depending upon Y the opening of the throttle H) by automatic means may be increased and the limit of the closing decreased by movement of the lever I00 in a counter-clockwise direction'on the quadrant I0I. Thus the'safety ranges of automatic operationmay be varied at the discretion of the pilot.

From the foregoing it will be readily seen that not only may the standard of operation of the automatic control be regulated by the pilot through the control lever I previously described, but also the operation of the throttle I9 is at all times subject to manual control by the pilot through the throttle control lever I00. Thus there is provided convenient means whereby the throttle I9 may be readily adjusted for variables affecting the operation of the engine and not reflected merely in the manifold pressure, such as for example variance inthe moisture content of the air, variance in temperature, variance in the quality of the fuel, creeping throttle conditions and other conditions out of the control of the pilot such as a breakdown of the automatic means.

Moreover, in the provision of the abutment rod 8 3' of Figures 1 and 8, there is provided means for locking the pressure responsive, mechanism 30 out of operation upon-appropriate adjustment of the control lever I to within a predetermined low pressure setting range and adjustment of the throttle valve I9 to a nearly closed position at which a characteristic inversion of the pressure the parts, which will now appear to those skilled in the art, may be made without departing from the scope of the invention. Reference is, therefore, to be had to the appended claims for a deflnition of the limits of the invention.

What is claimed is:

1. A throttle control, comprising, in combination, engine manifold pressure responsive means for automatically adjusting said throttle. manual control means for. adjusting said manifold pressure responsive means, stop means for limiting the adjustment, of said throttle by said automatic means at a predetermined position of said throttle, connecting means arranged for the adjustment of said throttle by said manual control means without interference from said stop means, means arranged for actuating said stop means into said limiting position upon a predetermined adjustment of said throttle, and separate means for, adjusting said stop means so as to vary the predetermined adjustment of said throttle at which said stop means may be actuated into said limiting position.

2. A throttle control, comprising, in combination, a walking beam, a condition responsive means operably connected at one end of said walking-beam to said throttle, a control member connected to saidwalking-beam at a point intermediate said opposite ends. and means controlled by the opposite end of said walking-beam for limiting in one direction the adjustment of said one end by said condition responsive means upon a predetermined adjustment of said throttle, whereupon said throttle may be adjusted by said control member unimpeded by said limiting means.

3. A throttle control, comprising; in combination, a walking-beam, floating lever, amanifold pressure responsive means pivotally connected to said floating lever at a first point thereon, means connecting said floating lever at a second point thereon to a first point on said walking beam, means for connecting said throttle to a second point on said walking beam whereby said throttle may be adjusted by said pressure responsive means in accordance with predetermined manitold pressure values, manual control means connected to said walking beam at a third point, and means pivotally connecting said floating lever at a third point to said manual control means whereby the aforesaid predetermined manifold pressure values may be selected by adjustment oi said manual control means.

4. A throttle control, comprising, in combination, a walking-beam, a floating lever, a manifold pressure responsive means pivotally connected to said floating lever at a first point thereon. means connecting said floating lever at a second point thereon to a first point on said walklug-beam, means for connecting said throttle to a' second point on said walking-beam whereby said throttle may be adjusted by said pressure responsive means in accordance with predetermined manifold pressure values, manual control means connected to said walking-beam at a third point, means controlled by said walking-beam for limiting the adjustment of said walking-beam by said pressure responsive means upon a predetermined adjustment of said control means,and

means pivotally connecting said floating lever at a third point to said manual control means whereby'the aforesaid predetermined manifold pressure values may be selected by adjustment of said manual control means.

5. A throttle. control, comprising, in combiner tion, a walking-beam, a floating lever, a manifold pressure responsive means pivotally connected to said floating lever at a first point thereon, means connecting said floating lever at a second point thereon to a first point on said walkingbeam, means for connecting said throttle to a second point on said walkin-beam whereby said throttle may be adjusted by said pressure responsive means in accordance with predetermined manifold pressure values, manual control means connected to said walking-beam at a third point, means controlled by said walking-beam for limiting the adjustment of said walking-beam by said pressure responsive means upon a predetermined adjustment of said control means, a lever arm pivotally mounted intermediate the opposite ends thereof, one end of said lever arm pivotally connected at a third point on said floating lever, and means reieasably connecting the opposite end of said lever arm to said manual control means whereby the aforesaid predetermined manifold pressure values may be selected by adjustment of said manual control means, said releasable connecting means being adapted to disconnect said lever arm and said manual control means upon movement of said pressure responsive means in a direction opposed by said limiting means.

6. A throttle control, comprising, in combination, condition responsive means for automatically adjusting said throttle, a manual control member, releasable means for connecting said control member and said condition responsive means for the adjustment of said condition responsive means by said control member, means for limiting the adjustment of said throttle by said conditlon responsive means upon a predetermined adjustment of said manual control means, and said releasable means arranged to disconnect said control member and said condition responsive means upon movement of said pressure responsive means in a direction opposed by said limiting means. I I

7. A device of the character described, comprising, in combination, condition responsive means for automatically adjusting a control device, a control member, releasable means for connecting said control member and said condition responsive means for the adjustment of said condition responsive means by said control member, and means for limiting the adjustment of said control device by said condition responsive means upon a predetermined adjustment of said control device, said releasable means being arranged to disconnect said control member and said condition, condition responsive means for automatical- 'said condition responsive means, and means conmeeting said first manual control member to said throttle for effecting manual control of said throttle independently of said second control member.

9. A throttle control, comprising, in combination an intake manifold pressure responsive means, a shaft driven by said pressure responsive means, said shaft operably connected tosaid throttle for adjusting the same, first stop means limiting the maximum opening of said throttle by said pressure responsive means, second stop means limiting the minimum opening of said throttle by said pressure responsive means, first manually operable means connected to said shaft for opening and closing said throttle free of said limiting means, whereby said throttle may be fully opened and closed under control of said first manually operable means, and second manually operable means connected to said shaft for varying said minimum and maximum limits for opening said throttle by said pressure responsive means.

10. In a hydraulic control valve of the class including a cylinder having control ports formed therein, a valve slidably mounted in said cylinder for controlling said ports, a control rod projecting from one end of said cylinder for slidably positioning said valve in said cylinder; the improvement comprising a member slidably mounted at the opposite end of said cylinder and arranged to releasably engage the valve so as to limit movement of said valve in one direction. a condition responsive means operably connected to said control rod, means for changing the datum of said condition responsive means, and means operably connecting said datum changing means to said member so as to limit movement of the valve in said one direction at a predetermined datum setting of said condition responsive means.

.11. In a device of the class including a hydraulic motor means for adjustably positioning a control device, a valve cylinder havin ports formed therein, a valve slidably mounted in said cylinder for controlling said ports so as to regulate the direction of flow of a fluid medium to said hydraulic motor means, a condition responsive means for actuating said valve in a first and in a second sense for determining the direction of movement. of said motor means; the improvement comprising a pin slidably mounted in one end of said cylinder, actuating means for said pin, said actuating means operably connected to said motor means, whereby said motor means may actuate said pin into engaging relation with one end of said valve for limitin the adjustment of said valve in one direction upon a predetermined adjustment of said control device, means for changing the datum of said condition responsive means, means connecting said datum changing means to the actuating means for said pin, and manual meansior jOlIltly operating said actuating means and said datumchanging means through said last mentioned connecting means.

12. A throttle control, comprising, in combination, an intake manifold pressure responsive means, a shaft driven by said pressure responsive means, said shaft operably connected to said throttle for adjusting the position of the same so as to automatically maintain a predetermined intake manifold pressure, a first stop member limiting the adjustment of the position of said throttle by said pressure responsive means in a throttle opening direction, manually operable means for adjusting the pressure setting of said pressure responsive means, a second stop member limiting the minimum pressure automatically maintainable by the pressure responsive means to a predetermined critical value, said manually operable means arranged so as to adjust the setting of said pressure responsive means tovalues greater and values less than said critical value, and means connecting said manually operable means to. said shaft so that said manually operable means may fully open and close said throttle independently of said pressure responsive means.

13. A throttle control, comprising, in combination, an intake manifold pressure responsive means, a shaft driven by said pressure responsive means, said shaft operably connected to said so as to automatically maintain a predetermined,

intake manifold pressure, a first stop member limiting the adjustment of the position of said throttle by said pressure responsive means in a throttle opening direction, manually operable means for adjusting the pressure setting of said pressure responsive means, a second stop member limiting the minimum pressure automatically maintainable by the pressure responsive means to a predetermined critical value, said manually operable means arrangedso as to adjust the setting of said pressure responsive means to values greater and values less than said critical value, means connecting said manually operable means to said shaft so that said manually operable means may fully open said throttle without interference from said first stop member and close said throttle independently of said pressure responsive means upon the setting of said pressure responsive means being at a value less than said critical value, and said second stop member being adjustable so asto vary said critical value.

14. A device of the character described, comprising, in combination, a condition responsive means for operating a control device so as to automatically maintain a predetermined condition, means for adjusting the datum of said condition responsive means, manual means for adjusting said datum changing means, means for limiting the condition automatically maintainable by said condition responsive means to values within a predetermined critical range, said manual means being arranged so as to adjust the datum of said condiiton responsive means to condition values other than the values within said critical range, mechanical linkage means directly connecting said manual means to said control device so that upon the adjustmentof the datum of said condition responsive means to a value other than the values within said critical range said control device may be manually adjusted independently of said condition responsive means.

15. A, throttle control, comprising, in combination, condition-responsive means for automatically adjusting said throttle so as to maintain a preselected condition, manual control means for adjusting said automatic means so as to vary said selected "condition; first means for limiting the adjustment of said throttle by said automatic means, said limiting means including a first member operably connected to said throttle and adjustably positioned in response to movement of said throttle, and a second-member actuated by said first member at a predetermined position of said throttle to render said automatic means inoperative for adjustingsaid throttle; a second means for limiting movement of said condition responsive means under a selected condition, and said manual control means being so arranged as to effect adjustment of said throttle without interference from said first and second limiting means. I

16. A throttle control, comprising, in combination, condition responsive means for automatically adjusting said throttle so as to maintain a preselected condition, manual control means for adjusting said automatic means so as to'vary said selected condition,- first means for limiting the adjustment of said throttle by saidautomatic means, said limiting means including a first member operatively connected to said throttle and adjustably positioned in response to movement of said throttle, a second member actuated by said first member at a predetermined position of said throttle to render said automatic means inoperative for adjusting said throttle, a

second means limiting movement of said conditionresponsive means under a selected condition, said manual control means so arranged as to effect adjustment of said throttle without interference from said first and second limiting means, and said second means including an adjustable member for varying the-conditions under which the movement of said condition resonsive means may be limited.

17. A control mechanism comprising, in' combination, a servo-motorsystem, means for controlling said system, condition responsive means, means for operative connecting said condition responsive means to said control means, means locking said condition responsive means from operative relation with said connecting means, and resilient means for permitting free opera;- tion of said condition responsive means during said locking operation.

18. In a device of the class including a hydraulic motor means for adjustably positioning a control device, a valve cylinder having ports formed therein and respectively connected to said motor means, a valve slidably mounted in said cylinder for controlling said ports so as to regulate the direction of flow of a fluid medium to said hydraulic motor means, a condition responsive means for actuating said valve in a first and in a second sense for determining the direction of movement of said motor means; the im provement comprising a pin slidably mounted in one endof said cylinder, actuating means for said pin, said actuating means being operatively connected tosaid motor means, whereby said motor means may actuate said pin into engaging relation with an adjacent one end of said valve for limiting the adjustment of said valve in one direction upon a predetermined adjustment of said control device.

19. In a device of the class including a hydraulic motor means for adjustably positioning a contrcl device, a valve cylinder having ports formed therein and respectively connected to said motor means, a valve slidably mounted in said cylinder for controlling said ports so as to regulate the direction of fiow of a fluid medium to said. hydraulic motor means, a condition responsive means for actuating said valve in a first and in a secondsense for determining the direction of ond spring connectedat the opposite end of said valve to bias the valve out of engaging relation with said pin.

20. A throttle control, comprising, in combination, condition responsive means for automatically adjusting said throttle, a first manual control member for adjusting said automatic means andv mechanically connectable to said throttle, limiting means determining the extent of adjustment of said throttle by said automatic means and permitting direct manual adjustment of said throttle by said first manual control member within a predetermined limited range, and a second manual control member for directly adjusting said throttle in such a manner as to vary the extent of adjustment of said throttle by said automatic means.

21. A throttle control, comprising, in combination, a walking beam, a condition responsive means for operating said throttle and operatively connected to one end of said walking beam, a control member pivotally connected to said walking beam at a point intermediate its ends, means connecting the throttle with a point of the walking beam other than said intermediate point, and means controlled by the opposite end of said walking beam for limiting in one direction the adjustment of said one end by said condition responsive means upon a predetermined adjustment of said throttle, whereupon said throttle may be adjusted by said control member unimpeded by said limiting means.

22. A throttle control, comprising, in combination, a walking beam, an engine manifold pressure responsive means including a fluid pressure responsive bellows, a control valve operated by said bellows, and a fluid motor means regulated by said valve for operating said throttle, said fiuid motor meansbeing operatively connected to one end of saidwalking beam; a manually operable arm pivotally' connected to said walking beam at a pointintermediateits ends, means connecting the throttle with a point of the walking beam other than said intermediate point, and a knocker arm controlled by the opposite end of said walking beam for limiting movement of said control valve by said bellows upon a predetermined adjustment of said throttle, whereupon said throttle may be manually adjusted through said arm unimpeded by said limiting means.

23. A throttle control, comprising. in combination, a walking-beam, a floating lever, a manifold pressure responsive means pivotally connected to said floating lever at a first point thereon, means connecting said floating lever at a second point thereon to a first point on said walking-beam, means for connecting said throttle to a second point on said walking-beam whereby said throttle may be adjusted by said pressure responsive means in accordance with predetermined manii'old pressure values, manual control means connected to saidwalking-beam at a third point, means controlled by said walking-beam for limiting the adjustment-of said walking-beam by means pivotally connecting said floating lever at a third point to said manual control means whereby the aforesaid predetermined manifold pressure values may be selected by adjustment of said manual control means.

24. A throttle control, comprising, in combination, condition responsive means for automatical- 1y adjusting said throttle, a first manual'control member for adjusting the setting of said automatic means, limiting me'ans determining the extent of adjustment of said throttleby said automatic means, a second manual control member connected to the throttle to directly adjust the throttle in addition to the adjustment of the throttle by the condition responsive means, and means connecting said first manual control member to said throttle for effecting manual control of said throttle independently of said second control member.

25. A throttle control, comprising, in combination, an intake manifold pressure responsive means, a shaft driven by said pressure responsive means, said shaft operatively connected to said throttle for adjusting the position of the throttle so as to automatically maintain apredetermined intake manifold pressure, a first stop member limiting the adjustment of the'position of said throttle by said pressure responsive means in a throttle opening direction, manually operable means for adjusting the pressure setting of said pressure responsive means, a second stop member for the pressure responsive means and limiting the minimum pressure automatically maintainable by the pressure responsive means to a predetermined critical value, said manually operable means Being arranged so as to adjust the setting of said pressure responsive means to values greater and values less than said critical value, and means connecting said manually operable means to said shaft 56 that said manually operable means may fully open and close said throttle independently ,of said pressure responsive means.

' to releasably engage said control element at the other end thereof, a second arm pivotally mounted and positioned between said knocker arm and second element, said second arm being arranged for actuation by said knocker arm into engaging relation with said second element to place said motor means in an inoperative relation. 28, The combination defined by claim 27 including an eccentric pin for pivotally mounting said second arm, and said eccentric pin adjustable to vary the relation between said second arm and second element.

29. The combination defined by claim 2'7 including a manually movable member for pivotally supporting said lever at a point intermediate said first and second points for effecting independent manual adjustment of said lever.

30. A throttle control for an aircraft engine having, an intake manifold in which there is a characteristic inversion of pressure upon closure of the throttle past a predetermined point, comprising, in combination, engine intake manifold pressure responsive means for positioning the throttle during normal operation, means for automatically locking the manifold pressure responsive means out of operation within the predetermined pressure inversion range, and manual means for manually actuating the throttle within said pressure inversion range.

31. A throttle control for an aircraft engine,

comprising, in combination, engine intake manifold pressure responsive means for positioning the throttle during normal operation to maintain a predetermined intake manifold pressure, manually operable means for varying the predetermined pressure setting of the pressure responsive means, means for automatically locking the manifold pressure responsive means out of oper ation within a predetermined low intake manifold pressure inversion range, and manual means for manually actuating the throttle within the stated low pressure inversion range.

32. The combination with an intake conduit of an internal combustion engine and a throttle valve for controlling flow of combustible mixture in said intake conduit, said intake conduit Having a characteristic pressure inversion upon adjustment of the throttle valve to maintain a pressure below a predetermined value; of manual means for actuating said throttle valve, automatic means responsive to engine intake pressure for positioning said throttle valve, means responsive to movement of said manual means for adjusting the pressure setting of said automatic means, and means for transferring from automatic to manual control of said throttle valve upon adjustment of the pressure setting of said automatic means to below the stated predetermined value.

33. The combination with an intake conduit of an internal combustion engine and a throttle valve for controlling flow of combustible mixture in said intake conduit, said intake conduit havin a characteristic pressure inversion upon adjustment of the throttle valve to maintain a pressure below a predetermined value; of manual means for actuating said throttle valve including a pilots control lever and a walking-beam intersive to movement of said manual means for adjusting the pressure setting of said automatic means including a cam operatively connected to said control lever, a cam follower, and linkage transferring from automatic to manual control of said throttle valve upon adjustment of the pressure setting of said automatic means to below the stated predetermined value, including an abutment rod so arranged as to limit in one sense movement of said bellows to prevent adjustment of the servo valve to a null position by said -bel-- lows and thereby looking out of operation said automatic means and transferring the control of said throttle valve to said manual means.

34. The combination with an intake conduit 4 of an internal combustion engine and a throttle valve for controlling flow of combustible mixture in said intake conduit, a pilot's control lever, a walking-beam mechanically interconnecting the control lever to the throttle valve, a bellows movable in response to changes in the pressure in the intake conduit, a servo valve actuated by the bellows to one side or the other of a null position,

' the cam follower, servo valve and bellows, said cam follower adjustably positioned by the cam to vary the null position of the servo valve with relation to the bellows and thereby the pressure setting of the bellows, an abutment rod so arranged as to prevent movement of the bellows in a sense to adjust the servo valve to a null position upon adjustment of thecam so as to decrease the pressure setting of the bellows to below a predetermined critical value and thereby locking out of operation the servo-motor and transferring the control of said throttle valve to said manual means within the stated critical low pressure range, a lock out pin movably mounted relative to said servo valve for locking the servo valve and thereby the servo-motor out of operation, a knocker arm interconnected with said throttle valve for actuating said lock out pin to a position for locking the servo valve and thereby the servomotor out of operation upon adjustment of the throttle valve past a predetermined critical open position so as to thereby transfer the control of said throttle valve to said manual means within the stated critical open range.

35. The combination defined by claim 34 including said abutment rod adjustably mounted to vary the critical low pressure range, and said knocker arm adjustably arranged to vary the critical open throttle valve range. i

36. The combination comprising a pair of axially arranged bellows, an abutment rod provided in one of said bellows for limiting the movement, thereof in one sense, another abutment rod in the other bellows for limiting the movement thereof in a second sense, at least one of said abutment rods being adjustably arranged so 20 as to vary the extent of permissible movement of said bellows.

37. In a device of the class including a fluid pressure operated motor means for adjustably positioning a control device, a valve cylinder having a control port formed therein and operatively connected to said motor means, a valve slldably mounted in said cylinder for controlling said port so as to control the direction of movement of said motor means, condition responsive means for actuating said valve in a first and in a second sense for determining the direction of movement of said motor means, and means for changing the datum of said condition responsive means;

the improvement comprising a member slldably mounted at one end of the valve, actuating means for said member, said actuating means being operatively connected to said datum changing means, whereby said member may be actuated into engaging relation with said valve for limiting the adjustment of said valve in one direction upon a predetermined adjustment of said datum changing means.

as. In a device of the class including a fluid pressure 'operated motor means for adjustably positioning a control device, a valve cylinder having a control port formed therein and operatively connected to said motor means, a valve slldably mounted in said cylinder for controlling said port so as to control the direction of movement of said motor means, condition responsive means for direction upon a predetermined adjustment of said control device.

HOWARD A. ALEXANDERSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date Gregg et a1 June 18, 1940 Bugatti Mar. 28, 1939 Halford et al Oct. 8, 1940 v 

